uniform vec3 color;
uniform sampler2D pointTexture;
varying float opacity;
void main() {
  if(opacity <= 0.0) {
    gl_FragColor = vec4(color, 0.05);
  } else {
    gl_FragColor = vec4(color, 1.0);
  }
  gl_FragColor = gl_FragColor * texture2D(pointTexture, gl_PointCoord);
}